Unidirectional-current-carrying device



March 5, 1929. o. GRONDAHL 1,704,679

UNIDIRECTIONAL CURRENT CARRYING DEVICE Original Filed Jan. 1925 INVENTORZ -A 0 Grandafil,

Patented Mar. 1929.

UNITED STATES PATENT OFFICE.

LABS O. GRONDAHL, OF PITTSBURGH, PENNSYLVANIA, ASSIGNOR TO THE UNION SWITCH & SIGNAL COMPANY, OF SWISSVALE, PENNSYLVANIA, A CORPORATION OF PENNSYLVANIA.

lJ'NIDIIRIEGTIOIN'AL-GURRENT-GARRYING DEVICE.

Original application filed January 7, 1925, Serial No. 1,111. Divided and this application filed July 28,

1927. Serial No. 209,016.

My invention relates to unidirectional current carrying devices, that is, to devices which have relatively high conductivity for current flowing in one direction but rela- 5 tively low conductivity for current flowing in the opposite direction.

The present application is a division of my co-pending application, Serial No. 1,111, filed January 7, 1925, for unidirectional ourrent carrying devices.

I will describe one form of device embodying my invention, and will then point out the novel features thereof in claims.

The accompanying drawing is a sectional 1 View showing one form of device embodying my invention.

Referring to the drawing, the device comprises a plurality of units, each of which is designated by the reference character A.

Each unit A comprises a metal plate orelectrode 10, and an electronically conducting compound 10 in intimate electrical contact with the surface of the plate. The compound 10 is preferably a compound of the metal which constitutes the plate, and preferably it is formed directly on-the plate and is integral therewith. As an-exa'mp-le, the plate 10 may be of copper, and the compound 10 may be cuprous oxide. As another example, the. metal plate 10 may be iron, and the compound may then be iron oxide. Against the layer of oxide 10 is placed a second electrode comprising one or more sheets 11 of a conductor of a soft, impressionable character, such, for example, as lead foil, and next to the conductor 11 is another plate 12 of conductive-material, such as copper.

The units A are spaced by separators 15 of conducting material to provide for ventilation. a

The elements of the device are pressed together by means not shown in the drawing, and the two outside metal plates 10 and 12 are used as terminals for passing electric current through the device; for this purpose terminal conductors 13 and 14 maybe provided,'if desired.

Although I have herein shown and detherein within the scope of the appended claims without departing from the spirit and scope of my invention.

Having. thus described my invention, what I claim is:

1. A .unidirectional current carrying device comprising a plurality of units connected in series and electro-eonductive spacing blocks of relatively small size located between each two adjacent units to provide for ventilation by the circulation of air.

2. A unidirectional current carrying device comprising a plurality of units connected in series, each unit being made up of a copper electrode having cuprous oxide formed chemically thereon, and electro-conductive spacing blocks of relatively small size located between each two adjacent units to provide for ventilation by the circulation of air.

3. A unidirectional current carrying device comprising a plurality of units connected in series, each unit consisting of a body made up of a metal having an electronically conducting compound of the metal formed thereonand integral therewith, said body constituting in and by itself an asymmetric conductor, and electro-conductive spacing blocks of relatively small size 10- cated between each two adjacent units to provide for ventilation by the circulation of air. 1

4. A unidirectional current carrying device comprising a plurality of units con- I nected in series, each unit consisting of a body made up of copper having cuprous oxide formed thereon and integral therewith, said body constituting in and by itself an asymmetric conductor, and electro-conductive spacing blocks of relatively small size located between each two adjacent units t; provide forventilation by the circulation o air.

In testimony whereof I afl'ix my signature.

LARS O. GRONDAHL. 

